Post herniorrhaphy pain syndrome, or inguinodynia is pain or discomfort lasting greater than 3 months after surgery of inguinal hernia. Randomized trials of laparoscopic vs open inguinal hernia repair have demonstrated similar recurrence rates with the use of mesh and have identified that chronic groin pain (>10%) surpasses recurrence (<2%) and is an important measure of success. Chronic groin pain is potentially disabling with neuralgia, parasthesia, hypoesthesia, and hyperesthesia. Patients may be unable to work, have limited physical & social activities, sleep disturbances, and psychologic distress. The management of inguinodynia is a difficult problem for many surgeons and 5–7% of patients experiencing post-hernia repair groin pain litigate.
Cause Neuropathic pain is defined as pain in the sensory distribution of an offended nerve. This may be due to preexisting stretch injury or intraoperative nerve injury. It is often described as stabbing and burning. Nociceptive pain includes somatic and visceral pain. Somatic pain may be due to chronic inflammation from tissue injury and is described as gnawing, tender, and pounding. Visceral pain can manifest as testicular and ejaculatory pain which may be associated with mesh ingrowth into spermatic cord structures.
Prevention
Nerves management Avoiding nerve entrapment and injury is critical. The current consensus is that routine identification and preservation of nerves is the best method for prevention. Transection of the nerves routinely is not a recommended strategy, as it can sometimes increase the pain further. It also increases sensory disturbances in the area of distribution of the transected nerve. No identification at all is the worst, and many surgeons are not making this identification. For example, in daily practice, surgeons identify all three inguinal nerves as three single nerves in less than 40% of the cases, while the literature shows that this identification can be done in 70-90% of the cases. The challenge is that the course of both ilioinguinal and iliohypogastric nerves is found to be consistent with that described in anatomical texts in only 42% of patients. However, these anatomical variations are readily identifiable.
Mesh Method of fixation has also been hotly debated with varying results reported with few consistent findings of decreased long term groin pain. However, fibrin glue seems to have a slight advantage. Types of mesh have also been studied, suggesting a small advantage for lightweight over heavyweight, and for biologic mesh over synthetic.
Hernia sac The role of hernia sac ligation is also being discussed. When ligation and excision of the sac is omitted, there is less reported short-term post-operative pain. However, the impact of this omission on long-term pain has not been widely studied so far.
Treatment
Nonsurgical management Evaluation and treatment can be very challenging in this patient population. Exam and imaging to exclude occult recurrence is important. Following that, use of antiinflammatories, nerve blocks, neuromodulators, and pain clinic referrals should be considered. Unless there is evidence of a recurrence, operative intervention should be deferred for at least 1 year since groin pain decreases with time elapsed from surgery.
Triple neurectomy and/or mesh removal If operative repair is chosen, mesh excision +/- triple neurectomy may be considered with small studies suggesting good outcomes. The largest series encompassing 415 patient, most following open or suture repair, demonstrates significant improvement following triple neurectomy. However, standard triple neurectomy does not address inguinodynia secondary to neuropathy of the genitofemoral nerve and the preperitoneal segment of its genital branch. But extension of the standard triple neurectomy to include the genitofemoral nerve has given good results, on a small series of 16 patients. Mesh removal should only be considered in last resort. Meshes are easy to place but difficult to remove, due to their incorporation inside the peritoneum. Other algorithms proposed have included diagnostic laparoscopy at the start for evaluation of adhesions, removal of mesh, and repair of any recurrences. If there is no improvement then a staged procedure to remove mesh and neurectomy may be considered.
Prognosis Chronic groin pain is more common than recurrence, and it may be lower following laparoscopic hernia repair. Pain often resolves with conservative measures. Following complete evaluation of patient and attempts at non surgical treatment, surgery may be considered. Various treatment algorithms exist with promising results.
… excerpt ends here. Continue reading the full article.
